zero-copy: Clarify to allocate/destroy GpuMemoryBuffer on any thread and use it on the main thread o

content/common/gpu/gpu_channel_manager.cc

Index: content/common/gpu/gpu_channel_manager.cc
diff --git a/content/common/gpu/gpu_channel_manager.cc b/content/common/gpu/gpu_channel_manager.cc
index 3d98e58e7292bc3f3cd18a0253dabe647897ca68..2ef78883337dacb6342c03dc3e4e3a0fa02f7b1a 100644
--- a/content/common/gpu/gpu_channel_manager.cc
+++ b/content/common/gpu/gpu_channel_manager.cc
@@ -18,7 +18,6 @@
 #include "gpu/command_buffer/service/memory_program_cache.h"
 #include "gpu/command_buffer/service/shader_translator_cache.h"
 #include "gpu/command_buffer/service/sync_point_manager.h"
-#include "ipc/message_filter.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_share_group.h"
 #if defined(USE_OZONE)
@@ -30,50 +29,6 @@ namespace content {
 
 namespace {
 
-class GpuChannelManagerMessageFilter : public IPC::MessageFilter {
- public:
-  GpuChannelManagerMessageFilter(
-      GpuMemoryBufferFactory* gpu_memory_buffer_factory)
-      : sender_(NULL), gpu_memory_buffer_factory_(gpu_memory_buffer_factory) {}
-
-  void OnFilterAdded(IPC::Sender* sender) override {
-    DCHECK(!sender_);
-    sender_ = sender;
-  }
-
-  void OnFilterRemoved() override {
-    DCHECK(sender_);
-    sender_ = NULL;
-  }
-
-  bool OnMessageReceived(const IPC::Message& message) override {
-    DCHECK(sender_);
-    bool handled = true;
-    IPC_BEGIN_MESSAGE_MAP(GpuChannelManagerMessageFilter, message)
-      IPC_MESSAGE_HANDLER(GpuMsg_CreateGpuMemoryBuffer, OnCreateGpuMemoryBuffer)
-      IPC_MESSAGE_UNHANDLED(handled = false)
-    IPC_END_MESSAGE_MAP()
-    return handled;
-  }
-
- protected:
-  ~GpuChannelManagerMessageFilter() override {}
-
-  void OnCreateGpuMemoryBuffer(
-      const GpuMsg_CreateGpuMemoryBuffer_Params& params) {
-    TRACE_EVENT2("gpu",
-                 "GpuChannelManagerMessageFilter::OnCreateGpuMemoryBuffer",
-                 "id", params.id, "client_id", params.client_id);
-    sender_->Send(new GpuHostMsg_GpuMemoryBufferCreated(
-        gpu_memory_buffer_factory_->CreateGpuMemoryBuffer(
-            params.id, params.size, params.format, params.usage,
-            params.client_id, params.surface_handle)));
-  }
-
-  IPC::Sender* sender_;
-  GpuMemoryBufferFactory* gpu_memory_buffer_factory_;
-};
-
 gfx::GpuMemoryBufferType GetGpuMemoryBufferFactoryType() {
   std::vector<gfx::GpuMemoryBufferType> supported_types;
   GpuMemoryBufferFactory::GetSupportedTypes(&supported_types);
@@ -99,14 +54,11 @@ GpuChannelManager::GpuChannelManager(MessageRouter* router,
       gpu_memory_buffer_factory_(
           GpuMemoryBufferFactory::Create(GetGpuMemoryBufferFactoryType())),
       channel_(channel),
-      filter_(
-          new GpuChannelManagerMessageFilter(gpu_memory_buffer_factory_.get())),
       relinquish_resources_pending_(false),
       weak_factory_(this) {
   DCHECK(router_);
   DCHECK(io_message_loop);
   DCHECK(shutdown_event);
-  channel_->AddFilter(filter_.get());
 }
 
 GpuChannelManager::~GpuChannelManager() {
@@ -169,6 +121,7 @@ bool GpuChannelManager::OnMessageReceived(const IPC::Message& msg) {
     IPC_MESSAGE_HANDLER(GpuMsg_CloseChannel, OnCloseChannel)
     IPC_MESSAGE_HANDLER(GpuMsg_CreateViewCommandBuffer,
                         OnCreateViewCommandBuffer)
+    IPC_MESSAGE_HANDLER(GpuMsg_CreateGpuMemoryBuffer, OnCreateGpuMemoryBuffer)
     IPC_MESSAGE_HANDLER(GpuMsg_DestroyGpuMemoryBuffer, OnDestroyGpuMemoryBuffer)
     IPC_MESSAGE_HANDLER(GpuMsg_LoadedShader, OnLoadedShader)
     IPC_MESSAGE_HANDLER(GpuMsg_RelinquishResources, OnRelinquishResources)
@@ -250,18 +203,18 @@ void GpuChannelManager::OnCreateViewCommandBuffer(
   Send(new GpuHostMsg_CommandBufferCreated(result));
 }
 
-void GpuChannelManager::DestroyGpuMemoryBuffer(
-    gfx::GpuMemoryBufferId id,
-    int client_id) {
-  io_message_loop_->PostTask(
-      FROM_HERE,
-      base::Bind(&GpuChannelManager::DestroyGpuMemoryBufferOnIO,
-                 base::Unretained(this),
-                 id,
-                 client_id));
+void GpuChannelManager::OnCreateGpuMemoryBuffer(
+    const GpuMsg_CreateGpuMemoryBuffer_Params& params) {
+  TRACE_EVENT2("gpu",
+               "GpuChannelManager::OnCreateGpuMemoryBuffer",
+               "id", params.id, "client_id", params.client_id);
+  Send(new GpuHostMsg_GpuMemoryBufferCreated(
+      gpu_memory_buffer_factory_->CreateGpuMemoryBuffer(
+          params.id, params.size, params.format, params.usage,
+          params.client_id, params.surface_handle)));
 }
 
-void GpuChannelManager::DestroyGpuMemoryBufferOnIO(
+void GpuChannelManager::DestroyGpuMemoryBuffer(
     gfx::GpuMemoryBufferId id,
     int client_id) {
   gpu_memory_buffer_factory_->DestroyGpuMemoryBuffer(id, client_id);